This commit makes the status of manager connections visible via the Manager
table in the database. Two new columns have been created for this purpose:
'is_connected' and 'status'. The former is a boolean flag, and the latter is a
string-string map which may contain the keys "last_error", "state", and
"time_in_state".
Requested-by: Keith Amidon <keith@nicira.com>
Reviewed by: Ben Pfaff.
Feature #3692.
I'm retaining the "managers" column in the Open_vSwitch table for now, but
I hope that applications transition to using "manager_options" eventually
so that we could drop it.
CC: Andrew Lambeth <wal@nicira.com>
CC: Jeremy Stribling <strib@nicira.com>
